1890.] NATURAL SCIENCES OF PHILADELPHIA. 57 



increase in size, piUi being very prominent. The lower molars dimin- 

 ish_ rai)i(lly from mi to ?)i;„ the latter being very small and lacking 

 the third lobe which is so characteristic of the Mesodonta ; the 

 pattern is mainly quadritubercular, the paraconid, if present, being 

 very small. 



ADAPISORICULUS, Lemoine. 



The type of this genus (see '85, p. 212, PL XI) is much smaller than 

 Adapisorex and well distinguished by the very lofty protoconid and 

 metaconid of the lower molars. It has otherwise the same charac- 

 ters upon a small scale. The family relationship with Adapisorex is 

 doubtful. 



Decticadapis is another genus of small mammals founded upon two 

 uj)per and one lower incisor teeth but not as yet well characterized. 



Pleuraspidotherium and Orthaspidotherkim have been considered 

 in the Ungulate series by Lemoine but Schlosser is correct in plac- 

 ing them in the Insectivora, although I cannot agree with him in 

 placing them near Erinaceus. While the molar patterns resemble 

 somewhat those of Erinaceus, the comj^lexity of the crowns of the 

 posterior premolars removes the idea of relationship which is sug- 

 gested by this resemblance. In Centetes, Gymnura and Ericulus we 

 observe a similar assumption of the molar pattern by the premolars. 

 In general, the reduction of the dental series between the median in- 

 cisor and last premolar affords conclusive evidence as to the rela- 

 tionship of these forms to the Insectivora. 



ORTHASPIDOTHERIUM, Lemoine. 



Propo--ed '8oa,p. 205. 



Gen. char.: Dentition if Ct pi m|. U p p e r m o 1 a r s as in 

 Pleuraspidotherium. Third and f o u r t h u ]> p e r p r e m o 1 a r s 

 with single external cusps. Inferior molars with 

 less distinct crests, and m-^ w i t h a t h i r d 1 o b e. Fourth 

 lower premolar simple with a posterior heel. 



This genus is evidently related as a more generalized form to the 

 following but is distinguished by its smaller size, simpler ])remolars,, 

 fuller dental series and relative absence of diastemata. 



PLEURASPIDOTHERIUM, Lemoine. 

 /*. Auvionieri, Lem. '78a, p. 1.5, type species. P. Delessei, Lem. '8(la, p. ]0. 



Gen. char.: Dentition if cl p?! mf . Upper molars mainly 

 quadritubercular, with small intermediate cusps. 



